Diaphragm-horn.



M. R. HUTCHISON.

DIAPHRAGM BORN APPLICATION TILED MAY 31, 1912.

1,094,403. Patented Apr. 21, 1914.

; UNITED STATES PATENT OFFICE.

MILLER REESE HUTCHISON, OF ORANGE, NEW JERSEY, ASSIGNOR TO LOVELL- MOCONNELL MANUFACTURING COMPANY, A CORPORATION OF DELAWARE.

DIAPHRAGM-HORN.

Patented Apr. 21, 1914.

Original application tiled Kay =11, 19ll,8erial No. 626,487. Divided and this application filed May 81,

. f 1812. Seriallio. 700,789.

To all whom it may concern.

Be it known that I, MILLER Rassa Humarsox, a citizen of the United States, and-resident of Orange, in the county of Essex "and State of New Jersev, have invented certain new and useful mprovemcnts in Diaphragm-Horns, of which the following is a specification.

'1 his application is a division of my rior application Serial No. 626,487 filed av 11th, 1911. In the said parent application have shown various dili'erent ways which :1 dia )hragm horn may be designed so that it will require somewhat less power to start it, and when running will ive forth a sound of less harshness than not produced in a horn in which the actuator directly engages with the diaphragm or with a wear piece rigid therewith. By means of the various constructions shown I may produce a sound of less harshness and at the same time save wear and tear of the diaphragm p the use of a non rigid, more or less yieldab e, elastic connection or coupling between the driver and diaphra This intermediate device when proper y designed and arranged receivcs the rigid thrust of the driver and at inharmonious speeds partialliv absorbs and partially transmits to the iaphragm the energy thus supplied to it, While at harmonious s ecds practically all of it is transmitted an little or none of it is used up in the elastic coupling device. In this way I somewhat lessen the abruptness with which the diaphragm is set in motion or the direction of its motion changed so that the uality of the sound produced is tempore accordin to the nature or extent of the yielding 0? which the connection is capable. Various different means for attaining this result are disclosed in the said prior application and in which the cushionin connection may be either cou led to the diaphragm or merely in contact tlieuewith and in which the connection may assume various non rigid elastic forms.

My present invention involves that t pa in which there is a transversely flexible e ongated member adjacent to one surfacepf the dia )hragm but preferably not in contact with the vibrating portion except where it is secured thereto, preferably at or near the center at tbclatter. By having the driver contact .with this cushioning member or a wear piece on the latter at a point removed fr0m the point at which the cushionin device 15 secured to the diaphragm the orce of the driver will be imparted to the diaphragm through the intermediate portion of the elastic connection by more or less modified or tempered thrusts rather than by blows imparted directly to the dia hrngm. The natural outward and return vibrations of the din ihragm may be completed or terminated wit 1 less interference and less abrupt change by reason of theslight bending or yielding of the connecting member. This ms advantages both as to power consumption, wear and tear, and quality of the note, especially at starting and stopping when the thrusts of the driver may be out of synchronism with the diaphragm. I prefer to secure the connecting member to the diaphragm positively, thereby the more surelv avoiding any lost motion between it and the diaphragm so that scraping, rattling, pounding or direct blows on the diaphragm by the cushioning device are prevented and the diaphragm and the cushioning member vibrate as a unit. The wear piece or other portion of the connecting member with whlch the 'driver contacts being more or less resiliently supported, it can give under the blows of the driver and thus the wear on it -as well as the driver will be reduced. In the case of powerful warning si nals such as are now standard in the mar cet, the wear and tour at these non-synchronous speeds is enormous as compared with the more natural synchronous speeds or harmonized speeds at which the natural outward and return vibrations of the steel diaphragm tend to hold the motor, and I have discovered that the yielding interposed between the positive thrust of the driver and the diaphragm may be sullicient to enormously decrease this wear and tear without being great enough to destroy the positivcness of the cam thrust or the overning action of the diaphragm upon t 1e cam. W iere therois a non-pus'itive connection between the intcrposcd member and the diaphragm or where the said member is too springythere may result movenu-nts of such member imlependently of the diaphragm at the non-syuchrouous speeds. and also that the interposed member is liable to vibrate in a different frequency from that of the diaphragm and this evcn at speeds phragm where the cam thrusts are at a rate harmonizing with the natural movements of the diaphragm. Hence I preferably avoid too great springiness as well as lost motion between the wear piece and the diaphragm so that any movements of the wear-piece indes method of operation described in my application, Serial Number 494,120, filed May 5th, 1909, that is to say the signal when driven by a suitable motor tends to be self-governing, so that the rotary driver tends to rotate at a speed which will give the note correspending to a natural or resonant frequency of the bodily swing of the whole diaphragm, which of course may be modified by and accord with the natural frequencyof a suitable select-ed resonator. In short, where the motor is of suitable power so that it is capable of varying its speed according to the work done in vibrating thediaphragm, any tendency of thcrotary driver to speed up beyond harmonious vspeeds to inharmonious speeds causes the projections thereon to intercept the diaphragm projection sooner with the result'that work done on the diaincreases in disproportionately greater ratios. with the result that the motor and driver are held substantially to harmonious speeds throughout wide variations in battery power. Substantially the same results are obtained in the present instance and are best insured when theresonator-is properly constructed and when the diaphragm is of relatively thin steel.

The cushioning member is preferably connected to thediaphragm at or near the center of the latter so that the maximum vibration is imparted to the latter by a given displacement of the cushioning device and when it is in the form of a stiff spring with one end rigidly secured to the center of the diaphragm and the other end supported adjacent to the periphery of the diaphragm the wear piece will be preferably mounted intermediate of the ends of the spring so that for a given movement of the center of the spring, the end of the spring at the center of the diaphragm, may-be given a greater movement and impart the maximum vibration. When the cushioning member is con structed and arranged so.that its range of yielding movement relatively to the dia-.

section 2 of a diaphragm case.

"phragmalong a radial line.

thereof, reference being had t-othe accompanying drawings, in which.

Figure l is a side elevation, partly in section, of a diaphragm horn embodying my invention and Fig. 2 is a horizontal section through the case.

My invention relates solely to the means for imparting the vibrations to the dia phragm and may be embodied in horns or signals of various differentcharacters. For purposes of illustration I have shown a resonator or projector 1 carried by the front The diaphragyn 8 is held between cork washers or the like 4, 5, by the marginal clamping por tions 6, 7, of the front section 2 and the rear section 8 of the diaphragm case. The clamping is effected by screws 9, which pass through openings in the clamping portions of the case sections and in the gaskets and the marginal region. of the diaphragm.

' The rear section 8 of the case is formed to receive the rotary driver 10, which is shown. as a disk provided with a plurality of peripheral cam projections. The axis of this rotary driver may be parallel to the diaphragm, as shown although this is not 'essen tial. Suitable means for rotating the driver at high speed is illustrated in the form of an .electric motor 11, the armature shaft 12 of which is prolonged into the rear section of the diaphragm case, there carrying the ro tary driver. The driver is preferably solidly mounted so as to deliver rigid thrusts to the cushioning connection 13, and to this end- -the bearing 14 of the rigid shaft 12 rigidly holds the shaft and is rigidly secured to the rear section of the diaphragm case. The bearing sleeve 14 has exterior cylindrical bearing upon the case at '14, 14, the axis of the shaft being eccentric to said cylindrical bearing surfaces, so that rotary adjustment of the sleeve adjusts the cam to or from the diaphragm.

The connection 13 is in the nature of arelatively stiff yet light spring tongue extending substantially parallel to the dia- The spring tongue is anchored at one point to the diaphragm and at another point to a stationary part with'thedriver coact-ing with the tongue at an intermediate point. The outer end is preferably held between the clamping members at the margin of the diaphragm and is spaced from the diaphragm while the other end is slightly bent toward the diaphragm and securely anchored -to the center thereof in an suitable manner as for instance by a rivet 25., A wear piece 18 is riveted to the tongue intermediateits end and the driver is placed in a corresponding position with reference to the diaphragm. The spring tongue operates as a lever in transmitting-the thrust in a cushioned manner to the diaphragm. By reason of the lightness of the tongue and the fact that it does not contact with the diaphragm along most of its length but may bend freely with the diaphragm, it does not interfere with the harmonious cooperation of the driving and driven member. In operation, the amount of sound produced by this assemblage will approach that produced by a rigidly actuated horn, according to the stillness of the spring tongue and the extent to which its wear portion intercepts the path of travel of the cam projections. The less yielding the connection, the more does it directly transmit the thrust of the cam and the less should be its normal rojection into the path of movement of t e cam projections. As the thrust of each projection begins and continues, the resultant motion is in part transmitted by the connection to the diaphragm and in part spent in flexing the connection. or this reason the degree of interception of the path of travel of the pTUjOQllOHS by the wear portion of the connection may be greater than the interception in the case of a wear piece fixed directly on the diaphragm. That is to say, other things being equal, the ielding connection has the efl'ect of pro l onging the time and reducing the intensity of each thrust. From th' it naturally results that the diaphragm is displaced less abruptly and violently and that the. sound is'smoother and setter than in the case oi a rigidly actuated signal. On the other hand the degree oi interception of the path of travel oi the projections by the near piece.

may be less than with the wear piece fixed on the diaphragm as the leverage and i'esili ency of the spring will give the diaphragm a suiiicient; initial thrust in starting the driver that it will properly engage on the return vibration and continue to properly engage during the normal operation. Thus with this construction it is not necessary to have so delicate a relative adjustment of the driver and wear piece Having th s deer? lliwl my I claim as no; and dwi 'r H) see to s la t en ti is:

i. In an alarm or signal, a diaphragm, a bar disposed losely adjacent to said diaphragm extending radially from the center to the periphery, said bar having a portion bent toward said diaphragm. and tightly clamped thereto, the remaind rof said bar being spaced slightly from said diaphragm and having the other end clamped rigid therewith, a wear-piece on said ban, adjacent to but out of alinement with the axis of said diaphragm and a rotor having a series of cam projections for successive engagement with said wear-piece, said bar being slightly resilient, under conditions of use.

in alarm or signal. a

subsiant amt. 31:: a X- invent ion. what by letpres i spaced therefrom along the major portion f the length of said bar, means for clamp ing said bar to said diaphragm adjacent to the center of the latter, a. casing including two clamping members, an annular washer means. for rigidly holding said clamping mtnnbcrs together with the said washer, the peripheral portion of said diaphragm and one end of said bar therebetween, and forcing means acting on said bar toward said diaphragm to impose on the latter a series of bodily swings of the center portion thereof.

3. In an alarm or signal, a diaphragm, a thrust transmitting member including a resilient bar having one end rigidly clamped adjacent to the edge of the diaphragm and having another portion secured to the diaphragm at the center of the latter and an impact member for delivering thrusts to said first-mentioned member at a point removed from the center of the diaphragm.

4. In an alarm or signal, a diaphragm, a spring having one end supported adjacent the periphery of the diaphragm and having the opposite end secured to the diaphragm at the center of the latter, a wear piece on said spring intermediate of the ends of the latter and a rotary impact member having engagement with said wear piece.

in an alarm or signal. of the class described, an elastic diaphragm having a sub stantialiy definite tin a )(lllt'ld of free bodily swing, an elongated spring member tightly secured adjacent to the periphery of the diaphragm, and also tightly secured to a central portion of the diaphragm, said spring member presenting a wearpiece spaced endwise from the portion secured to the diaphragm, the stiffness of said spring member and the arrangement of said Wearpiece being such that in full operation the movements of the wearpiecc bear a deti nite relation to the natural swing of the diaphragm. in rmnhination with a rotary am inning projections .lormed. and. spaced to have, a positiie forcing engag ncnt with said i\'cai'-pi( 'e, and a. motor atapted t vary its speed in accordance with the work done on the diaphragm and of sullicient power to start and drive said cam up to and at speeds causing cam contacts at intervals cta'responding' to and harnmnizing with the movements of said wearpiece.

(3. In an alarm or signal of the class described a relatively thin elastic metallic dia phragi'n, an elongated spring member having one portion tightly secured in fixed position at a point remote from the center of the diaphragm and having another portion maintained in fixed relation to a central po ion of the diaphragn'i. said member "piece soared along said phrag m fin-ring spring member and the relative arrangement of said wearpiece being such that in normal full-speed operation the movements of the wearpicce are harmonized with the to and fro bodily swing of the diaphragm, in combination with a rotary cam having projections formed and spaced to have a positive forcing engagement with said wearpiece through a portion of the movement and to permit another portion of the movement to be free elastic, and a motor adaptedto vary its speed in accordance with the work done, and of sullicient power to start and drive said cam up to and at speeds causing cam contacts at intervals corresponding to and harmonizing with the natural swing of the vibratory parts.

7. In an alarm or signal of the class described, an elastic diaphragm having a sub stantially definite time period of bodily swing, a rotary rum and means for driving it up to a speed of synchronism of cam contacts and diaphragm swings, in combination with an elongated element between the cam and diaphragm and having a portion tightly secured to a central part of the diaphragm and a cam engaging portion, said ortions being spaced apart radially of t e diaphragm and said cam engaging ortion being spaced away from said diap ragm and slightly movable toward and from the same to cause and permit continuous bodily swing of the diaphragm with a cam push for every swing at normal working speeds but cushioning independent interfering movements occurring at sub-normal speeds.

Signed at Excelsior in the county of Hennepin and State of Minnesota this 22nd day of May A. D. 1912.

Witnesses;

JOHN F. BUDENCK, GEo. P. DICKINSON. 

